Fix 1.0.0-alpha9 pre-release audit findings: examples README link and timeout-sweep starvation backoff

Follow-ups from the pre-release code audit for 1.0.0-alpha9. Two small, independent fixes plus a repository hygiene tweak.

L2: examples README link is broken

The link to the notification-delivery guide in the request-validation examples README points two directory levels up, but the README is nested four levels below the module root, so it resolves to a path that does not exist. Corrected to point at the module-root docs/ directory.

I1: timeout sweep can starve later due tokens

The cron timeout sweep loads a bounded, deadline-sorted batch of due tokens. When a due token's effective workflow definition cannot be resolved (a mid-edit or in-progress config import, or a pruned pinned version), the sweep kept the token's passed deadline and moved on. Because the batch is bounded and sorted by deadline, such a token re-occupies a slot at the head of the batch on every run, so once enough accumulate the due tokens behind them are never processed.

The node-not-in-definition branch already handled this by deferring the deadline forward by a back-off window. This extracts that deferral into a shared helper and calls it from the definition-unresolvable branch too, so both defer instead of one starving. A kernel test replays a due token whose definition was removed out from under it alongside a healthy due token, and asserts the unresolvable token's deadline advances by the back-off window while the healthy one still fires.

Repository hygiene

Generalize the local .gitignore entry from AUDIT.md to AUDIT*.md so per-cycle audit scratchpads are ignored too.

No behavior change for existing correct configurations; the timeout fix only affects the previously-starving edge case.